Coaxial cable connectors that require crimping are associated with certain disadvantages. Crimping tools tend to wear out with repeated use, and crimping does not provide a satisfactory seal. A number of crimpless connectors have been developed which attempt to overcome these problems.
One type of crimpless connector receives a compression sleeve, which is first broken away from a plastic ring mounted on the connector, and then slid over the cable and finally inserted into the annular cavity between the inner wall of the connector and the jacket of the cable. A tool is used to push the compression sleeve fully into the connector with a snap engagement.
A problem with this connector is that it can be awkward to break the compression sleeve away from the connector and then thread it onto the cable, particularly when used in field installations where there may be adverse weather conditions. The compression sleeve can as well be inadvertently threaded onto the cable backwards, and it can also be dropped and lost.
An alternative crimpless connector has more recently been provided, which permits the cable to be secured to it by means of an integral grip bushing that surrounds an internal mandril defining an annular gap that may receive the jacket and braiding of an inserted cable. The bushing can thereafter be moved so as to squeeze and hold the braiding and jacket of the cable, forming a seal therewith. While this grip bushing cable connector has many advantages, it does not lend itself to use with coaxial cables of different thicknesses.
Within the cable television industry, RG6 and RG59 cable are the most prevalent standard. Common RG6 and RG59 cable has a central conductor, a dielectric insulator with a single aluminum foil cover, one layer of braided shield surrounding the foil covered dielectric insulator, and a plastic insulating jacket covering the braided shield.
In addition to common RG6 and RG59 cable, so called “Tri Shield” and “Quad Shield” versions are also increasingly widely used. Tri Shield cable has a second layer of foil which covers the braided shield. Quad Shield cable has both a second layer of foil and a second layer of braided shield over the second layer of foil.
As a result of the additional shielding layers, Tri Shield and Quad Shield RG6 and RG59 cables have overall thicknesses or diameters greater than that of common RG6 and RG59 cable. The standard diameter of common RG6 cable, for example, is 0.272 inches. For Tri Shield RG6 cable the standard diameter is 0.278 inches. For Quad Shield RG6 cable the standard diameter is 0.293 inches.
Due to the close tolerances required for the known grip bushing connectors, a single connector cannot properly accommodate and attach to all three thicknesses of cable. At least two different sizes of connector are required: one for common cable and Tri Shield cable, and a second one for Quad Shield cable.
This situation is inconvenient for installation technicians, and represents an undesirable cost to cable television companies and suppliers. Not only do two separate inventories of connectors have to be maintained, the two different sizes of connectors can be easily mixed up, leading to installation difficulties.